A pressure sensor that uses a MEMS (Micro Electro Mechanical Systems) technology includes, for example, a piezoresistance change type and an electrostatic capacitance type. On the other hand, a pressure sensor that uses a spin technology has been proposed. In the pressure sensor using the spin technology, a resistance change corresponding to strain is sensed. The sensitivity of the resistance change corresponding to the strain depends on a material of a spin valve film, for example. For example, in a strain sensing element that is used in the pressure sensor or the like using the spin technology, it is desirable to enhance the sensitivity.